Originally Posted by Citti34
My furnace (1995 Dutchmen) was blowing cold air when the heater was set to 90. I went and unplugged two wires on the furnace and heard the igniter turn on and it started working. Think there's a short? Here's a video http://youtu.be/fbivn-QqSOA
What kind of furnace is it. I don't think you have a short. I would guess a relay going bad in your control panel. If you get me the type, I could find a wiring diagram and help diagnose it a little better.